FILE - In this Oct. 30, 2009 file photo, al-Shabab fighters sit on a truck as they patrol in Mogadishu, Somalia. The U.S. military said Friday, May 5, 2017 that a service member has been killed in Somalia during an operation against the extremist group al-Shabab as the United States steps up its fight against the al-Qaida-linked organization. (AP Photo/Mohamed Sheikh Nor, File)

MOGADISHU, Somalia (AP) — A U.S. service member has been killed in Somalia during an operation against the extremist group al-Shabab — the first U.S. combat death in the country in more than two decades — as the United States steps up its fight against the al-Qaida-linked organization in a country that remains largely chaos.

“We do not believe there has been a case where a U.S. service member has been killed in combat action in Somalia since the incident there in 1993,” U.S. Africa Command spokesman Patrick Barnes said Friday. The United States pulled out of Somalia after that incident in which two helicopters were shot down in the capital, Mogadishu, and bodies of Americans were dragged through the streets.

In a statement, the U.S. Africa Command said the service member was killed Thursday during the operation near Barii, about 40 miles (64 kilometers) west of Mogadishu. The statement said U.S. forces had been conducting an advise-and-assist mission with Somalia’s military.

Al-Shabab via its Shahada News Agency said “an air landing operation by U.S. special forces was thwarted in Lower Shabelle province and a number of their soldiers were killed and wounded,” the SITE Intelligence Group reported.

Both the United States and Somalia in recent weeks have declared new efforts against al-Shabab. President Donald Trump has approved expanded military operations against the extremist group, including more aggressive airstrikes and considering parts of southern Somalia areas of active hostilities.

A Somali intelligence official confirmed the U.S. military operation, saying U.S. forces in helicopters raided an al-Shabab hideout near the Somali capital on Thursday night and engaged with fighters.

The official, who spoke on condition of anonymity because he was not authorized to speak to the media, said the helicopters dropped soldiers near Dare Salaam village in an attempt to capture or kill extremists in the area. The official said the fighters mounted a stiff resistance against the soldiers.

Somalia’s new Somali-American president, Mohamed Abdullahi Mohamed, last month declared a new offensive against al-Shabab, which is based in Somalia but has claimed responsibility for major attacks elsewhere in East Africa.

Also last month, the U.S. military announced it was sending dozens of regular troops to Somalia in the largest such deployment to the country in roughly two decades. The U.S. Africa Command said the deployment was for logistics training of Somalia’s army.

The U.S. in recent years has sent a small number of special operations forces and counter-terror advisers to Somalia and has carried out a number of airstrikes, including drone strikes, against al-Shabab.

The extremist group, which was chased out of Mogadishu years ago but continues to carry out deadly attacks there, has vowed to step up the violence in response to the moves by Trump and Mohamed.

Aid groups have raised concerns about the new military efforts, saying civilians could be at risk as hundreds of thousands are displaced by a drought that threatens roughly half the country’s population of 12 million.

Pressure is growing on Somalia’s military to assume full responsibility for the country’s security as the 22,000-strong African Union multinational force that has been supporting the fragile central government plans to leave by the end of 2020.

The U.S. military has acknowledged the problem. The AU force will begin withdrawing in 2018, and head of the U.S. Africa Command, Commander General Thomas Waldhauser, has said that if it leaves before Somalia’s security forces are capable, “large portions of Somalia are at risk of returning to al-Shabab control or potentially allowing ISIS to gain a stronger foothold.”

Fighters linked to the Islamic State group are a relatively new and growing challenge in the north of the country, which has seen a quarter-century of chaos since dictator Siad Barre fell in 1991.